(Dembitsky 2006). Its biosynthesis has not been fully elu-cidated. A recent study (Cracan and Banerjee 2012) has included experiments aiming at elucidating, at least partly, the biosynthesis of pivalic acid. The enzymes Geobacillus kaustophilus isobutyryl-CoA mutase fused (GkIcmF), where IcmF is an ICM with ICM and GTPase activities, andCmIcmF (Cm is Cupriavidus metallidurans) were used to document the conversion of isovaleryl-CoA to pivalyl-CoA. However, it should be noted that the activity of the enzymes in the isomerization of isovaleryl-CoA to pivaloyl-CoA is two to three orders of magnitude lower than that in the reaction of butyryl-CoA yielding isobutyryl-CoA.